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针对电机轴承高速化载荷高的需求以及磁流体轴承具有的自润滑密封、可靠性高、高速、低摩擦润滑等一系列优点,对磁流体轴承在不同条件下的性能开展了研究。首先从理论上推导了磁流体粘度的相关公式,通过采用Matlab软件在外加磁场的条件下,对磁流体的粘度进行了修正,并给出了磁流体轴承润滑的粘温、粘压特性。其次,采用有限元分析方法设计了外加磁场,并对轴承内部的磁场分布进行了分析。研究结果表明,在外加磁场的作用下,磁流体轴承润滑的粘度发生变化,同时,相较于传统普通轴承,磁流体轴承的承载能力得到提高,能在高温、高速的工况下工作。 相似文献
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针对磁流体在磁场中粘度测试的特殊性,研制了一种新型的旋转法磁流体粘度测试实验台,该实验台可通过测试带动工作气隙内磁流体作旋转剪切运动所需的力矩来推算得出磁流体的粘度,满足磁流体在磁场中的粘度测试要求。利用所设计的实验台对矿物油基Fe3O4磁流体的粘度进行了测试,研究了外加磁场、温度及磁流体中磁性颗粒含量对其粘度的影响规律。结果表明:磁流体的粘度随着外加磁场强度的增加而增大,当磁场强度增大到一定程度时,其粘度变化逐渐趋缓;随着温度的升高,磁流体的粘度呈不断下降趋势,在有外加磁场作用情况下,其粘度下降的幅度要远大于无外加磁场作用的情况;随着磁流体中所含磁性颗粒质量分数的增加,其粘度逐渐增大,当磁性颗粒质量分数小于30%时,粘度增加缓慢,但当质量分数超过30%以后,粘度则急剧增大。 相似文献
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磁流体对伺服阀力矩马达动态特性的影响 总被引:7,自引:1,他引:6
利用磁流体在外加磁场作用下具有较高饱和磁化强度和较大粘度的特点,提出了采用磁流体改善伺服阀力矩马达动态特性的方法。通过把磁流体添加到伺服阀力矩马达的工作气隙,来增加力矩马达的阻尼,改变力矩马达的动态响应特性,提高力矩马达及伺服阀的稳定性,从而有助于抑制和消除伺服阀自激振荡及噪声。通过对磁流体作用机理及力矩马达磁回路的分析,给出了磁流体作用力数学模型,以及添加磁流体和不添加磁流体的力矩马达动态数学模型,采用MATLAB/Simulink对添加磁流体和不添加磁流体的伺服阀力矩马达动态响应特性进行了分析,给出了分析结果,并通过激光位移传感器对伺服阀力矩马达动态响应特性进行了试验研究。仿真及试验结果表明,磁流体可增加伺服阀力矩马达的阻尼比,从而提高伺服阀力矩马达的稳定性和抗干扰能力。 相似文献
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磁场中磁流体粘度测试系统的实现 总被引:1,自引:2,他引:1
介绍了一种磁流体粘度测试系统,可用于研究磁流体动密封磁场对磁流体粘度的影响。在该系统中驱动外筒的电机转速的变化与填充在固定内筒和外筒之间的磁流体粘度成反比,而模拟磁流体动密封运行工况的磁路则提供了定量的可变的外磁场,另外基于外推法的温度测量方案可精确地对测试时的温度进行控制,最后使用标准液体标定的结果表明其相对误差小于0.83%。 相似文献
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建立了磁流体滑动轴承的弹流润滑数学模型,利用考虑热效应的Renolds方程,采用多重网格法、多重网格积分法和逐列扫描法,对磁场作用下的水基磁流体润滑滑动轴承的弹流性能进行数值分析。对比了有无磁场作用下的水基磁流体弹流润滑数值模拟结果,并探讨了磁感应强度对其膜厚和压力的影响。结果表明,在有磁场作用的条件下,不同磁粉体积分数下的水基磁流体的润滑膜膜厚比没有磁场作用时有所增加,但压力没有明显变化;在不同磁感应强度条件下,随着磁感应强度的增加,水基磁流体润滑膜厚增加,压力没有明显变化。 相似文献
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可控阻尼磁流体滑动轴承的设计及减振性能研究 总被引:2,自引:0,他引:2
设计一种具有可控阻尼效应的铁磁流体轴承。该新型磁流体轴承采用阻尼可控磁流体代替传统普通滑动轴承内外环间隙中的润滑油,可通过外磁场调节内磁流体的黏度阻尼,来控制轴承的振动。建立由伺服电机、涡流传感器和数据采集系统组成的磁流体轴承性能测试系统,研究不同转速和电流下轴承的振动情况。结果表明:在外磁场作用下,磁流体轴承的振动幅度明显减小;同时施加的电流越大,对振幅的抑制作用越明显,表明磁流体滑动轴承的减振效果明显,且其阻尼是可控的。 相似文献
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粘度指数改进剂对油性极压剂润滑性的影响研究 总被引:2,自引:1,他引:1
在150ZN基础中,用四球试验的五个粘度指数改进剂对六种油性极压剂的润滑性影响。结果证明多数粘度指数改进剂可提高油性极压剂的综合磨损值。 相似文献
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Fe3O4磁流体润滑摩擦因数试验研究 总被引:2,自引:0,他引:2
利用MMW-1万能摩擦磨损试验机,测定不同磁性颗粒含量、载荷和旋转速度下Fe3O4磁流体润滑剂的四球摩擦副的摩擦力矩,并计算出相应的摩擦因数。试验结果表明,磁流体润滑膜具有良好的减摩能力,其中质量分数为10%的磁流体摩擦学性能最优,其摩擦因数相对于基液最大可降低35%左右。摩擦学性能得以提高主要是由于磁性颗粒的增粘作用,使油膜增厚,微滚动效应则导致摩擦力减小。 相似文献
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添加纳米Fe3O4 润滑剂磨损性能试验研究 总被引:6,自引:0,他引:6
采用化学共沉淀发制备了纳米级铁磁流体润滑剂,利用MMW-1万能摩擦磨损试验机,测定了添加纳米Fe3O4润滑剂在不同速度、添加量和载荷下的摩擦学性能,并对减摩抗磨机制进行了研究。结果表明,添加纳米Fe3O4粒子的润滑油表现出了良好的抗磨减摩性能,并能够显著改善基础油的承载能力,最大可以提高16.5%。其减摩抗磨机制为,由于纳米微粒大多为球状,能起到类似“球轴承”的作用,从而提高润滑性能;另外,由于纳米颗粒的增粘作用,从而提高承载能力。 相似文献
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Tribological effects of fullerene (C60) nanoparticles added in mineral lubricants according to its viscosity 总被引:1,自引:0,他引:1
Bon-Cheol Ku Young-Chul Han Jung-Eun Lee Jae-Keun Lee Sang-Ho Park Yu-Jin Hwang 《International Journal of Precision Engineering and Manufacturing》2010,11(4):607-611
In this study, the tribological behaviors of fullerene nanoparticles-added mineral oil were investigated as a function of
viscosities (e.g., 12, 30, 55, 96 and 145 mm2/s). Extreme pressure and anti-wear properties were evaluated using a four-ball tester, respectively. The lubrication tests
were performed with a disk-on-disk tester for different normal loads. Tribological properties were evaluated by measuring
friction surface temperature and the friction coefficient, and interpreted in terms of the Stribeck curve. We note that the
weld points of the raw- and nano-oil increased as the oil viscosity increased and weld points for all nano-oil were higher
than those of raw oil. Also the wear scar diameters of the raw- and nano-oil decreased as the oil viscosity increased and
wear scar diameters for all nano-oil were less than those of raw oil. Also, we have found that the difference of friction
coefficient between raw oil and nano-oil was outstanding when the viscosity of raw oil was low and the normal load is high.
Our results indicate that the addition of fullerene additives in lubricant was more effective when the viscosity of raw oil
was low under the higher normal load conditions. 相似文献
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几种金属纳米粒子作润滑脂添加剂的试验研究 总被引:4,自引:0,他引:4
用Falex四球摩擦磨损试验机考察了镍、钴、铬、钼、铁-钴及铁-镍合金纳米粒子作为添加剂加入润滑脂的摩擦学行为。结果表明:添加纳米粒子的润滑剂均具有较好的减摩抗磨性能和较高的承载能力(PB值),合金纳米粒子比金属单体纳米粒子的添加效果好,纳米粒子质量分数在3%左右时润滑脂具有较佳的摩擦学性能。 相似文献
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Ferrofluid squeeze film in a long journal bearing 总被引:2,自引:0,他引:2
A theoretical study and comparison were made of squeeze film behaviour in an infinitely long journal bearing using the ferrofluid flow models of Neuringer–Rosensweig, Jenkins and Shliomis with uniform and non-uniform magnetic fields. Expressions were obtained for the pressure, load capacity and response time of the squeeze film using the flow models of Jenkins as well as Shliomis. The results corresponding to the Neuringer–Rosensweig model were deduced from the Jenkins model. Computed values of dimensionless load capacity and response time were displayed in tabular form. Their values increased with increasing values of the eccentricity ratio in all the three models. They decreased or increased according to whether the values increased were those of the Jenkins material constant or the rotational viscosity parameter of Shliomis. A uniform magnetic field could not produce magnetic pressure in the Neuringer–Rosensweig model, but it could affect the bearing characteristics in the Shliomis model owing to the rotational viscosity. The load capacity and squeeze time are more in the case of a non-uniform magnetic field than in the case of a uniform magnetic field. 相似文献
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含硫极压抗磨添加剂在菜籽油中的摩擦学性能研究 总被引:3,自引:2,他引:3
利用四球磨损试验机考察了以硫化异丁烯和硫化棉籽油作为菜籽油极压抗磨添加剂时的摩擦学性能,通过测定2种添加剂在不同含量下的最大无卡咬负荷(pB)和不同条件下的磨斑直径(WSD),分析和研究了载荷、摩擦时间、添加剂含量对菜籽油摩擦学性能的影响。试验结果表明:硫化异丁烯可以明显提高菜籽油的承载能力和抗磨性能,硫化棉籽油对提高菜籽油的承载能力和抗磨性能效果不明显,硫化异丁烯在菜籽油中的承载能力和抗磨性能明显优于硫化棉籽油。试验还表明添加剂的含量并非越高越好,否则WSD值将增大。 相似文献
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Efrén Andablo-Reyes Juan de Vicente Roque Hidalgo-Álvarez Connor Myant Thomas Reddyhoff Hugh A. Spikes 《Tribology Letters》2010,39(1):109-114
This article examines the use of ferrofluids to control starvation in lubricated contacts. Starvation in a ball–plate contact
is experimentally studied under sliding–rolling conditions using a Mini Traction Machine (MTM). Friction is measured and the
experimental results are presented in the form of Stribeck curves. The volume of lubricant is controlled in such a way that
no free bulk oil is present in the vicinity of the contact. An abrupt change in the slope of the Stribeck curve in the Hydrodynamic
Lubrication zone is interpreted as the onset of starvation. It is then shown that the use of ferrofluids in the presence of
a magnetic field distribution can change the conditions at which this onset of starvation occurs. Different magnetic field
distributions are tested for different values of load and ferrofluid viscosity. It is proposed that ferrofluid lubricants
in conjunction with a suitably positioned magnetic field can be used to promote replenishment, and thus control and reduce
lubricant starvation. 相似文献